Pump



PUMP

Fil'ed June 17. 1924 Z INVENTOR.

MLL/f/N hf Tao/1290 WQ 44k ATTORNEY Patented May 10, 1927.

are STATES WILL'J'QAM THOMPSON, OF BERKELEY, CALIFORNIA.

PUMP.

Application filed-June 17,

'My invention relates to pumps and particularly to gas circulating pumps ot the double-acting reciprocating type.

An objectot the invention is to provide a pump of the character described having inlet valves acting independently of the fluid. pressure so that valve leakage may be reduced to a minimum.

Another object of the invention is to proride a pump of the character described which will maintain a substantially continuous flow of the fluid to be pumped at a'predetermined pressure. p

The invention possesses other objects and features otadvantage, some of which. with the foregoing", will be set forth in the following description of the preferred form of my invention which is illustrated in the drawings accompanying and forming part ot the specification. It is to be understood that I do not limit myself to the showing made by the said drawings and description, as I may adopt variations of the preferred setforth in the claims.

Referring: to said drawings 2- Figure l is a plan view. chiefly in section, of the fluid pump of my invention.

Figure 2 is a side sectional view on the line 2-2"in Figure 1.

Briefly expressed, the pump of my invention comprises a cylinder having an inlet port openinggthrough its sides intermediate its ends. a hollow piston arranged for reciprocation over said port. and a passage in said piston communicating with said port. Opening fromopposite ends of the piston cavity are valve controlled ports opening into the cylinder. the valves therefor being arranged to he operated by movement of the piston rather than by the fluid pressure relations as is the usual pump inlet valve. Outlet valves arranged to operate only at a predetermined pressure are arranged in opposite ends of the cylinder. so that the output of the pump may be delivered at a substantially invariable pressure.

As here shown. the pump of my invention comprises a casino 3 in which is provided a cylinder aperture 4 having end walls 5 and 6 and sidewalls 7. A piston 9 is arranged tor reciprocation in the cylinder. the piston being preferably as here shown, in the form at a cylindrical. shell defining a cavity 11 55 therein and having; valve seats 12 provided in the opposite ends thereof. Fluid is artaken i intermediate the end walls.

form within the scope of my invention as 1924. Serial no. 720,481.

ranged to be introduced into the piston cavity 11 through an inlet port 14 which is preferably provided in the cylinder wall .7

A longitudinally extending slot 16 is provided in the piston wall and registers with the port 14 to allow the introduction of fluid to the piston cavity during" the reci rocation ot the piston. it will thus be noted that by forming the piston slot 1.6 slightly longer than the stroke of the piston that the port 14 and slot 16 will be constantly in registration. thus allowing the passage of fluid therethrough independently of the position of the piston in the cylinder. 1

To control the flow oi fluid from the pistonravity into the cylinder, valves 17, arranged to tit the seats 12. are provided. As here shown. the valves 17 fixedly mounted on a valve stem 18 extending longitudinally through the piston and slidably carried in hearings 19 provided in the end walls 5 and 6 ot the cylinder, the valves 17 being in oppo'sel relation and spaced so that when one valve isseated in one seat 12. the other will be held out of its seat. In this manner. it will be noted that at the beginning of a stroke of the piston. the forward seat 12 will contact with a valve 17 to close the Forward, end of the piston cavity, after which the valves and piston will be moved "forward together during; the balance of the stroke. Since movement of the piston is thus arranged to close the torward valve, a

quicker closing will result than if a valve is provided which must be operated by the pressure against the head of the. cylinder. thus reducing the possible bacl: flow of fluid to a minin'uun. With the rearmost valve thus unseated, an unimpaired flow of fluid is allowed from the piston cavity into the portion of the cylinder beingvacated by the piston. Complete evacuation of fluid from the forward portion of the cylinder is pro vided for by arranging the valves to abut the end walls of the cyl nder at the ends of the strokes of the piston.

D scharo'e of fluid from the cylinderends is preteii-ably provided for by means of ad justahle spring: hall-valves 20 provided at opposite ends of the cylinder to allow the escape of fluid through passages 21 associ ated therewith. these passages terminating in nozzle openings 22. It will now be noted that with fluid supplied continuously to the piston cavity at a substantially constant llU pressure, the compression and discharge of fluid occurs in the portion of the cylinder adjacent one end of the piston While the portion of the cylinder being vacated receives a new charge. The foregoing operation, in eonihiinilion with til 2 action ol' the adjustable valves :20, provides a rnactiicall continuous discharge at lluid, no that the pump of my invention is particularly useful for circulating: a gas at a eonatant pressure as in particularly required in refrigerating plants and the like.

To provide for the read longitudinal movement ol the ends oi the valve [\lIGHl it in the bearings 19, I preferably provide longitudinal passages 23 extendingfrom the ends thereof and opening through the side of the stem adjacent the valves. To prevent escape of 'l'lttitl lll'tilllltl the piston, piston rings 25 are prefer-ah];- providtul at opposite ends of the piston.

Actuation ot the piston may he ellected in any desired manner. do here shown, a transverse slot 26 provided centrally ot' the piston in which a hloch ii" is arranged to he reciprocatcd hv naeaua o l a wrist pin 28 carried on a disc in mounted on a shalt 2:31. for rotation in the frame and revolrdilv engaged in the hloclt 2?. Revolution oil the disc is thus arranged to produce a reciprocativo movement of the platen, the speed of such movement: being least at. the rude oi? the strokes thereof. thus avoiding airy hammering ol' the platen. it will he noted that the engagement of the block in its seat prevents rotation of the pint on.

This disc isarranged to he rotated. in an desired manner. As hero shown, rotation of the disc is eti'ceted hy means of a worm gear 32 mounted on the shaft; 31 and arranged to he driven h means of a worm gee r mounted on a niotor driven shaft: 3

it will liUW he noted that a pump has been provided which is :ioait1ive, smooth, and ellicielrt in action and which is arranged to occupy a minimum of: space.

1 claim:-

1. A fluid pump coinpriaing a cylinder having;- closed ends, hearings provided in said ends, an inlet? port arranged in a side tliereof intermediate said ends, and outlet; ports arranged adjacent said ends; a piston having a cavity therein arranged to connnunicate with said inlet port and having outleta arranged in oppoaite ends thereof; a valve t-jitlll :slidahly mounted in said h aringa; and tippoaitel disposed valves .lixed on said atom and arranged to alternately en- ;Eage said piston cavity outlets, said valves and stein heing arranged to he reciprocated with said piston.

:2. A fluid pinup comprising a, cylinder having closed ends, an inlet: port arranged in a side thereof intermediate said ends, and outlet valves arranged adjacent said ends; a piston. having a cavity therein arrztnged to eonnnunicate with said inlet port and having outlet opening-a arranged in opposite ends lheroof; means for reciprocating :said piston; a valve stein extending through said piston cavity outlet: openings and slidahl mounted in said cylinder ends; and valves lixed on said valve atom in opposed relation and arranged to he reciprocated with said piston, the l()l\\'tll(l valve being seated in the :liorn'ard pinton opening, and the rearward valve being unsealed during a given stroke ol? the pit-"ton.

8. 111 a double actingfltluid pump a c;v1,inder having an inlet port; intermediate its v-ntla and outlet ports :uljacent its ends, a hollow reciproeahle pinion arranged to have the iavity thereof in conslant' connnuuication with said inlet port and having valve openings arranged in the ends thereol, hearing: sockets provided at the enda of said cyliuder. a valve stenr mounted for reciprocation in and lltlWtQll said sockets, and oppoaitelv diaponed valvea mounted in lixcd relation on said stein and arranged to alternately engage said piston valve openings upon l'LYCTllll'tlttlllUIl ol mid pie-ton.

In teatiinony \vhcreot', 1, have hereunto set in hand at Oakland, California, this id day of J nne, 1.92%.

lVlLLI. t

l H. 'llilOMlSON. 

